MCP, the Model Context Protocol, is a standard protocol for connecting AI apps to external tools and data. Tools expose themselves in one standard way, and any app that supports MCP can connect to them.
The problem: M×N integrations#
Before MCP, every AI app that wanted an external tool had to build its own custom integration. Every tool, in turn, had to build a separate integration for each app.
With M apps and N tools, that is M×N integrations to build and maintain. Three apps and four tools already means 12.
The fix: one standard#
With MCP, each tool is wrapped once as an MCP server. Each app adds MCP support once. After that, any app can use any server.
| Without MCP | With MCP | |
|---|---|---|
| Integrations to build | M×N | About M+N |
| Adding a new tool | One integration per app | One MCP server, usable by every app |
| Swapping a tool | Change the app's code | Connect a different server |
Build the tool once, and it works everywhere that speaks MCP.
Like USB for AI tools#
Before USB, every device had its own connector. USB standardized the interface, so any device works with any port. MCP does the same for AI tools: one interface between apps and tools.
What MCP does not do#
MCP handles discovery and communication: which tools a server has, what arguments they take, and how to call them. It does not handle trust or permissions.
A tool connected through MCP is not automatically safe to use. Your code is still the safety boundary: validate arguments, check authorization and confirm risky actions as for any tool.
Short line#
MCP is a standard protocol between AI apps and tools. It turns M×N custom integrations into one MCP server per tool and MCP support once per app, like USB for AI tools. It handles discovery and communication, not trust, so a connected tool is not automatically safe.
Key takeaways#
- Without a standard, M apps and N tools need M×N custom integrations.
- MCP standardizes how tools expose themselves, so a tool built once works in every MCP app.
- Each tool becomes an MCP server. Each app adds MCP support once.
- Think of it as USB for AI tools.
- MCP handles discovery and communication, not trust or permissions.